1. Field of the Invention
The present invention relates to a guiding locking piece, and more particularly, to a locking piece used in pod for locking and supporting the mask.
2. Description of the Prior Art
In the process of wafer fabrication in advanced foundries or semiconductor Fabs at present era, yield rate decides whether a semiconductor Fab. profits or not. Therefore managing to enhance the yield rate becomes the most important topic for managers. Among the ways to enhance the yield rate, SMIF system is used to reduce particle contamination during the storing and transporting process of wafer fabrication.
In the prior art, as shown in FIG. 1 and FIG. 2, a common pod 10 comprises upper and lower cover members 11 and 12, wherein two support devices 13 are set up opposite to each other on two sides of the lower cover member 12 and said support devices 13 comprises several stoppers 14 and holders 15 deploying on them. In addition, a restricting device 16 is further deployed on one of the adjacent sides of two opposite support devices 13 and transforms the structure of lower cover member 12 into the shape of an upside-down U with two support devices 13 and an adjacent restricting device 16. Therefore, when a mask is put into lower cover member 12, the structure shaped like an upside-down U can lock and support the mask.
When upper and lower cover members 11 and 12 of pod 10 cover a mask, stoppers 14 and holders 15 deployed on support devices support the brim of the mask. But due to the gap between the upper and lower cover members 11 and 12, displacement will occur along the direction of the side that has no restricting device, i.e. the opening of the upside-down U shaped structure. Thus, not only the duration of mask is reduced due to its adhesive wear caused by adhering support devices 13 and restricting device 14, but the yield rate is also reduced due to the particles caused by friction.
Concerning the defects of the prior art, the present invention provides a structure of guiding locking piece that not only facilitates the leading of mask into pod, but also effectively locks the mask and thus extends the duration of the mask, reduces friction between mask and pod, and prevents the yield rate from being reduced by particle contamination.